Lipsticks have been used for many years to impart color to the lips. The color helps to define the mouth area while imparting cosmetic shades that are suitable with fashion trends. Such lipsticks, in general, are made of an oily vehicle comprising fat or oil stiffened to a desired consistency with waxes of various types which also serve to raise the melting point and improve the physical stability. The color is ordinarily provided by insoluble pigments such as lakes of dye finely dispersed in the oily vehicle and one or more fluorescein dye derivatives which serve to stain the lips. A solvent for the dye is also included for increasing the effectiveness of this staining on the lips.
In recent years, attempts have been made to provide a lipstick which will impart a uniform long-lasting coloring to the lips and thus lessen the need for frequent reapplication. This has been accomplished by increasing the concentration of the dye and pigment in the conventional lipstick formulation to greater than 10% by weight. However, lipsticks containing such high concentrations of dye and pigment have been found to impart a dry non-uniform "cakey" look to the lips. This is particularly undesirable since current fashion trends are directed to producing a "wet" or "moist" look on the mouth. As a result, emollients, lubricants, and moisturizers are added in increased amounts to counteract the "cakey" results of the high dye and pigment containing lipstick formulations. However, these materials may impart a soft mushy easily breakable structure to the lipstick. Furthermore, these materials themselves are usually short-lived on the mouth since they are mechanically removed. In addition, these materials tend to act as vehicles for the dyes and pigments causing "creeping" or "feathering" on the outer edges of the mouth. This eliminates the sharp line of definition of the mouth area for which the product is applied.
Another approach to improving wear properties of lipstick has been to employ high staining organic dyes, for example, Red 21,14032, Orange 5,3655 and others. Unfortunately, it has been found that when high staining organic dyes are used in concentrations greater than 0.5% by weight of the lipstick, to achieve longer color wear, the stick structure of the lipstick is decreased in strength to an unsatisfactory level. Where it has been attempted to use the high staining organic dyes in amounts less than 0.5% by weight of the lipstick, it has not been possible to achieve the desired longer color wear.